A desmutagenic factor isolated from burdock (Arctium lappa Linne)

Abstract A desmutagenic factor was isolated from burdock ( Arctium lappa Linne). This factor reduced the mutagenicity of mutagens that are active without metabolic activation, such as 4-NO 2 -1,2-DAB and 2-NO 2 -1,4-DAB, as well as mutagens such as ethidium bromide, 2-aminoanthracene, Trp-P-1 and Trp-P-2 requiring S0 for metabolic activation. It is resistant to heat and proteolytic enzymes and sensitive to treatment with MnCl 2 . The partially purified principles had a molecular weight higher than 300 000 and showed characteristics of a polyanionic substance. An irreversible diminution of the mutagen was confirmed by treatment of 2-NO 2 -1,4-DAB or Trp-P-2 with the burdock factor.